Double Sling (Plus)

I use antiperspirant under my boobs (and I wear an underwire), and it helps prevent the nasty heat rashes I'm otherwise prone to in the summer. But, if that's not an option for you, you can try something like these: Quilted Bra Liners, or Double Boob Sling, (Plus Sized) And yes, I know they are on the website of the Evil Empire, but it was just a quick search. I'm sure you can find them elsewhere.